Groundwater contamination by hydrocarbon-based chemicals primarily occurs in industrialized areas where such chemicals are in daily use. Over a period of time, spills, and leaks from pipes, storage tanks, etc., seep into the ground and migrate into the groundwater and are spread over large underground areas. Since many communities use well water for drinking purposes, slight amounts of contaminates such as perchloralethylene and trichloralethylene, which are known to cause cancer, must be removed or reduced to safe levels. Various methods for extracting the contaminated water for processing purposes are disclosed in U.S. Pat. No. 4,611,950, "Method and Apparatus for Removing Contaminants From Soil" by Richard J. Russomano; No. 4,600,508, "Contamination Removal System" by Kenneth A. DeGhetto; No. 4,167,973, "Process for Chemical Decontamination of Layers of Earth and/or Water Contaminated with Organic Materials" by Ernst Forte, et al., and No. 4,435,292, "Portable Method for Decontaminating Earth" by James L. Kirk, et al.
After extraction, the most obvious decontamination method is to filter the water and gas through activated charcoal filters. However, the size of the filters and the amount of charcoal required, make the use of such systems prohibitively expensive for groundwater reclamation.
If it were only a matter of stripping the hydrocarbon contaminates from the water a simple steam or hot-air stripping tower could be used. In these systems, the steam or heated air is used to vaporize the hydrocarbon contaminates with the result that clean water can be extracted. However, what remains to be disposed of are contaminated steam and the vaporized hydrocarbon contaminates. In many cases, these can be released into the atmosphere. However, if no such release can be tolerated, such as in the County of Los Angeles, Calif., and if the contaminates must also be removed from the soil, the steam or hot-air stripping process by itself is insufficient. Furthermore, if the contamination is extensive and or if the water must be removed at a slow rate to avoid surface subsidence, a system may be in operation for a number of years. Thus, any system must make efficient use of energy. Therefore, in the prior art, a condenser and gravity separator are used to liquify the hydrocarbons and steam exiting the stripping tower separating the two. The resulting contaminated water is recycled, while the condensed hydrocarbons, are collected for subsequent processing or disposal. However, this prior art system does not handle the problem of extraction or processing of moisture ladened soil and gas.
Therefore, a primary object of the subject invention is to provide a system for removing hydrocarbon contaminates from water and moisture ladened gases extracted from the soil.
Another primary object of the subject invention is to provide a system for removing hydrocarbon contaminates from water and moisture-ladened gas that works on a closed-loop principal with no release of contaminates to the atmosphere.
It is a further object of the subject invention to provide a system for removing hydrocarbon contaminates from water and moisture-ladened gas that is very efficient and consumes a minimum amount of energy.